Dependency Injection (DI) helps us to change the behavior of parts of our program on the fly. This is especially neat when you want to test your domain services against a mocked data-store. But what if you need to change the behavior of your API based on a request header?
Yesterday I had a discussion with my colleague Robert Kranenburg about this. He showed an example of a console application changing its behavior based on an argument. I took the idea and converted it into .NET Core 3.1 code to change behavior based on a cookie.